The Voyage of Bran
The Voyage of Bran, a Celtic pre-Christian mythic tale of quest and displacement, would be more familiar to Western audiences. It is believed to have been written down around 700 AD, although it has an earlier oral history. It has been inspiration to several other tales, which are set in a more explicitly Christian context. You can find an abridged text here, or the full text by clicking here (both texts translated by Kuno Meyer).
Postal stamps hailing from the Faroe Islands, which seem to depict the Christian version of the Bran or somesuch myth:
